Treating hydrocarbon fluids



Patented June 22, 1943 UNITED STATES PATENT OFFICE 2,322,673 TREATING HYDROCARBON FLUIDS William J. Sweeney, Elizabeth, N. J., assignor to Standard Oil Development Company, a corpo ration of Delaware No Drawing. Application September 14, 1940, Serial No, 356,831

4 Claims. (01. 196 -52) This invention relates to the catalytic con- 'version of hydrocarbons containing aromatic .constituents and more particularly relates to the catalytic conversion of aromatic extracts;

In the catalytic cracking of higher boiling hydrocarbons suchas gas oils and the like, it has been found that the condensate oil separatedfrom the reaction products is refractory alytically cracking certain a omatic stocks such.

as aromatic extracts or extr cts of hydrocarbon oils containing aromatic co stituents.

According to my inve ion, relatively light aromatic hydrocarbon e racts such as sulphur dioxide extracts of ke osene containing aromatic constituents and extracts of similar hydrocarbons, are subjected to catalytic cracking in the presence of a suitable cracking catalyst to produce about to 20% of low boiling compounds boiling below about 200 or 250 F. My invention is concerned with the catalytic cracking of relatively light aromatic hydrocarbon extracts as distinguished from relatively heavy aromatic extracts of relatively heavy oils. Aromatic extracts of relatively light distillates such as gasoline or kerosene are preferred feed stocks for my invention. A solvent extract of a gasoline produced from a crude containing a relatively large amount of aromatic constituents forms a good feed stock for my invention. Other similar aromatic fractions having the characteristics of the relatively light aromatic extracts above described may be used.

My invention will now be describedin greater detail. Airaction or hydrocarbon mixture containing aromatic constituents obtained by suitable solvent extraction of distillates such as a gasoline produced from a crude oil containing a relatively large amount of aromatic constituents, kerosene or heavy kerosene is heated to an elevated temperature of about 800-1000 F., in order to substantially completely vaporize the solvent extract. The solvent extract is obtained in any well-known solvent extraction process, as for example by treating kerosene or the like with liquefied sulphur dioxide to separate solution of aromatic constituents in the sulphur dioxide is separated from the remaining oil, the.

solvnt or sulphur dioxide is removed and the remaining extract forms the feedstock for my invention. Any suitable solvent may be used in the solvent extraction.

The aromatic extract heated to an elevated temperature in any suitable manner is passed through a chamber containing a suitable catalyst for catalytically cracking the aromatic extract to produce lower boiling hydrocarbons. After the desired extent of cracking or conversion is obtained, the reaction products are passed to a fractionating tower to separate relatively light hydrocarbons from a condensate 'oil withdrawn from the bottom of the fractionating tower.

If ,desired, side streams of hydrocarbon frac-' tions may be removed from the side of the fractionating tower. The fractionation step is preferably so carried out that a light fraction boiling up to about-212 F.,is obtained and-this fraction is particularly suitable as a solvent. Or the fractionation may be so carried out that a motor fuel containing gasoline constituents is obtained. A

The condensate oil may be passed to storage or! may be further treated in any desirable manner and then recycled to the catalytic cracking zone or chamber. If desired, the condensate oil without further-treatment may be recycled to the catalytic cracking zone. I

As catalysts in my process, I may use natural clays, activated days, such as hydrated silicates of alumina, synthetic clays such as synthetic gels containing alumina and silica and catalysts supported on alumina or the like. Instead of having a stationary bed of catalyst through which the vapors of the aromatic extract are passed, I may inject powdered catalyst into the aromatic extract vapors or the powdered catalyst may be. 'mixed with the liquid aromatic extract before the catalyst particles to burn off the carbona ceous deposit. It is necessary to carefully control the temperature during regeneration to prevent the catalyst particles from being raised to too high a temperature, as high temperatures are harmful to the catalyst.

aromatic constituents from the kerosene. The Specific examples of my invention are included in the data given in the following table in which an activated clay was used as the catalyst:

desirable to solvent extract cycle oils from catalytic cracking or thermal cracking operations Aromatic S01 extract S01 extract extract from tifi ts $3.? i it? sene o m o e Feed stock from East containing from crude Texas crude aromatic oil containing oil constituents aromatic constituents Feed stock inspections: I

Gravity.... A. P. I 26. 8 l9. 8 17. 6 Aniline point 43 -9.0 -4.0 Initial boiling p 300 422 'iZl btiiiig iaa i2? 00101 R 3?"... 10.0 2. 66 ll. 6 Carbon residue 0.02 '0. 0. 01 Length of cracking c 4 4 4 Av. catalyst tome 861 854 854 Feed rate-vol. o l/vol. catJhr 0. 6 0.6 Q. 6 Conversion on feed: Gas wei ht percent.. 2. 3 3. 3 3. 0 Gasoline ..volume percent stabilized)-. 48.4 26.9 21.6 Excess butane. .volume percent 0 0 0 Cycle oil do 43. 6 78. 9 76. 9 Coke and handling loss weigbt percent; 7. 4 6. 4 9. 0 Gasoline inspections:

Gravity ..A. P. I 40.3 43.4 41.5 5. 5 10 7. 7 Octane No. 0. F. B. MM 79.5 84 86.6 Aniline int -F 14 -5 (-5 D a L v 158 5 10. 5 15 212 11 21 26 257 a 17. 5 32. 5 38 Final boiling point 408 416 412 Cycle oil inspections Gravity l9. 2 l7. 7 15. 8 Aniline point 14 30 60% 470 .89 470 From the above data', it will be seen that the catalyticv cracking of aromatic extracts results in relatively high yields of lower boiling hydrocarbons suitable for use as solvents. My invention can also be carried out to produce aromatic gasolines. 1 am not to be restricted to the above examples as different yields may be obtained by use of different cracking conditions.

The solvent extracts to be catalytically cracked according to my process are preferably so chosen that they contain relatively large amounts of single ring aromatic compounds rather, than double ring aromatic compounds. When a virgin gas oil is treated successively with a selective solvent or with a series of selective solvents in order of increasing solvent power, the

for removal of double ring aromatic compounds. In these cases it might be economical to further extract such cycle stocks to produce a cut containing primarily single ring aromatic compounds. It is intended that single ring aromatic specific dispersions between about 110 and 175,

last. By well known methods of solvent extra tion, it is possible then to separate a virgin gas oil into three cuts, namely onecontaining primarily double ring aromatic compounds. one containing primarily single ring aromatic compounds. and a residual raflinate containing naphth enes and parafllns. For my process, which is designed primarily for the production oil can be used as feed to this catalytic cracking process. In some cases it is economically ,of low boiling aromatics in the gasoline and fore a primary or single extract from the gas and rafiinates substantially free of all types of aromatics may be defined as those having specific dispersions below about 110.

While I have given specific examples of my invention, it is to be understood that they are merely by way of illustration and that I am not to belimited thereto, and that modifications and changes may be made within the scope of the invention without departingfrom the spirit of my invention.

Iclaimf 1. A method of producing a low boiling hydrocarbon material suitable for use as a solvent from a. hydrocarbon 011 stock containing straight chain aliphatic hydrocarbons, singlering aromatic hydrocarbons and double -ring hydrocar-' bons which comprises extracting said hydrocarbonv oil stock with a suitable selective solvent to remove substantially all of the double ring aromatic' hydrocarbons, further extracting the remaining 011 stock with a secondsolvent suitable for extracting from said stock a fraction containing a relatively large amount oi single ring aromatic compounds, heating said fraction containing large amounts of single ring aromatic compounds to an elevated temperature and passing itthrough a catalyst chamber wherein it is maintained under cracking conditions in the presence of catalyst particles for a sumcient time gas oil.

to produce a substantial amount of lower boilfraction containing large amounts of single ring in; constituents and separating a relatively low I aromatic compounds has a boiling range between boiling fraction ofhigh aromatic content from about 300 and about 600 F.

the cracked products. 4. A method according to claim 1 in which 2. A method according to claim 1 in which 5 the fraction containing large amounts of single the original hydrocarbon oil stock is a virgin ring aromatic compounds has a relatively low anilinepoint, below about 50.

3. A method according to claim 1 wherein the WILLIAM J, SWEENEY. 

